CVE-2016-4648 in Mac OS X
Summary
by MITRE
Audio in Apple OS X before 10.11.6 allows local users to obtain sensitive kernel memory-layout information or cause a denial of service (out-of-bounds read) via unspecified vectors.
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Analysis
by VulDB Data Team • 09/06/2022
The vulnerability identified as CVE-2016-4648 represents a critical security flaw within Apple's macOS operating system affecting versions prior to 10.11.6. This issue resides within the audio subsystem and demonstrates a classic out-of-bounds read vulnerability that can be exploited by local attackers to gain unauthorized access to kernel memory information. The vulnerability stems from insufficient input validation and memory management within the audio processing components of the operating system, creating a pathway for malicious actors to extract sensitive kernel memory layout data through unspecified vectors that remain undisclosed in the public CVE record.
The technical implementation of this vulnerability involves improper bounds checking within kernel-level audio processing functions that handle various audio input/output operations. When legitimate audio data is processed through these functions, the system fails to properly validate array indices or buffer sizes, allowing attackers to manipulate input parameters to trigger memory reads beyond allocated boundaries. This flaw specifically affects the kernel's memory management subsystem where audio data structures are handled, potentially exposing critical kernel memory addresses, stack contents, or other sensitive information that could be leveraged for privilege escalation or further exploitation attempts.
From an operational impact perspective, this vulnerability poses significant risks to macOS environments as it enables local users to either extract kernel memory layout information or cause system instability through denial of service conditions. The ability to obtain kernel memory layout information directly aligns with CWE-125 Out-of-bounds Read, which is categorized under the broader weakness of improper input validation in memory safety contexts. Attackers could potentially use this information to bypass kernel address space layout randomization protections, making subsequent exploitation attempts more predictable and successful. The out-of-bounds read condition can also lead to system crashes or hangs, effectively creating a denial of service scenario that impacts system availability and user productivity.
The exploitation of this vulnerability typically requires local system access, making it less immediately dangerous than remote attacks but still highly concerning for enterprise environments where local access might be compromised. Security researchers have noted that such kernel-level vulnerabilities often map to ATT&CK technique T1068, which covers the use of privilege escalation techniques through kernel exploits. The vulnerability's classification as a local information disclosure issue means that attackers with legitimate user accounts could potentially leverage this to gain insights into the system's memory structure, potentially enabling more sophisticated attacks such as kernel exploitation or advanced persistent threat campaigns.
Organizations should implement immediate mitigation strategies including prompt deployment of macOS 10.11.6 updates or later versions that contain the necessary patches for this vulnerability. System administrators should also consider implementing additional monitoring for unusual audio processing activity or memory access patterns that could indicate exploitation attempts. The vulnerability demonstrates the importance of maintaining up-to-date operating system versions and highlights the risks associated with delayed patch management in enterprise security environments. Security teams should also review their incident response procedures to ensure readiness for potential exploitation attempts targeting kernel-level vulnerabilities, particularly those that could enable privilege escalation or information disclosure attacks.